Convertible Preferred Stock and Stockholders' Equity (Deficit) - Warrants for shares of common stock (Details)
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1 Months Ended |
3 Months Ended |
6 Months Ended |
12 Months Ended |
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Jun. 04, 2021
USD ($)
$ / shares
shares
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Apr. 23, 2020
$ / shares
shares
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Jun. 30, 2021
USD ($)
$ / shares
shares
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Jan. 31, 2021
USD ($)
$ / shares
shares
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Apr. 30, 2020
USD ($)
$ / shares
shares
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Mar. 31, 2020
USD ($)
$ / shares
shares
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Jun. 30, 2021
USD ($)
$ / shares
shares
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Mar. 31, 2021
shares
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Jun. 30, 2020
USD ($)
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Jun. 30, 2021
USD ($)
$ / shares
shares
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Jun. 30, 2020
USD ($)
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Dec. 31, 2020
$ / shares
shares
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Apr. 23, 2021 |
Nov. 09, 2020
shares
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Apr. 18, 2019
shares
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Class of Stock [Line Items] |
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Deemed dividend from warrant repricing |
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$ 0
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$ 134,000
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$ 0
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$ 134,000
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Proceeds from Warrant Exercises |
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$ 0
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$ 37,000
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Lisa Walsh |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
187,500
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12,756
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Warrant term |
5 years 4 months
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Common Shares |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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236,369
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Warrants to purchase shares of common stock for cash | shares |
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250,000
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Issuance of common stock upon warrant exchanged | shares |
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1,360,244
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2,086,251
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June 4th Purchase Agreement |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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2,275,000
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2,275,000
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2,275,000
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Exercise price of warrants | $ / shares |
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$ 2.55
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$ 2.55
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$ 2.55
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Fair value of warrant |
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$ 3,153,000
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$ 3,153,000
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$ 3,153,000
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Common Stock Price | $ / shares |
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$ 2.52
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$ 2.52
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$ 2.52
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June 8th Purchase Agreement |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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2,040,000
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2,040,000
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2,040,000
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Exercise price of warrants | $ / shares |
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$ 2.61
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$ 2.61
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$ 2.61
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Fair value of warrant |
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$ 2,375,000
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$ 2,375,000
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$ 2,375,000
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Common Stock Price | $ / shares |
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$ 2.25
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$ 2.25
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$ 2.25
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April 2020 public offering |
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Class of Stock [Line Items] |
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Exercise price of warrants | $ / shares |
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$ 3.25
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$ 0.01
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Fair value of warrant |
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$ 475,000
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Common Stock Price | $ / shares |
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$ 2.50
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Combined shares price | $ / shares |
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$ 3.24
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$ 3.25
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Deemed dividend from warrant repricing |
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$ 2,606,000
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$ 134,000
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Proceeds from Issuance of Warrants |
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$ 4,750
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Issuance of common stock upon warrant exchanged | shares |
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475,000
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Warrant term |
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5 years
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Warrant |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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281,000
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281,000
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281,000
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Proceeds from Issuance of Warrants |
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$ 889,000
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Warrant | Lisa Walsh |
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Class of Stock [Line Items] |
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Exercise price of warrants | $ / shares |
$ 3.00
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Fair value of warrant |
$ 570,000
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Common Stock Price | $ / shares |
$ 4.77
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Warrant | Common Shares |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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1,000,000
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1,000,000
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1,000,000
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Exercise price of warrants | $ / shares |
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$ 4.46
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$ 4.46
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$ 4.46
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Fair value of warrant |
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$ 579,000
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$ 579,000
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$ 579,000
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Common Stock Price | $ / shares |
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$ 4.50
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$ 4.50
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$ 4.50
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Net proceeds |
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$ 2,300,000
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Warrant term |
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5 years
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5 years
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5 years
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Warrant | January 2021 [Member] |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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1,221,675
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Warrants to purchase shares of common stock for cash | shares |
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305,419
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Exercise price of warrants | $ / shares |
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$ 4.20
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Fair value of warrant |
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$ 567,000
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Common Stock Price | $ / shares |
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$ 3.85
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Proceeds from Warrant Exercises |
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$ 2,900,000
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Warrant term |
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5 years
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March 2020 Warrant |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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227,679
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Exercise price of warrants | $ / shares |
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$ 6.40
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Fair value of warrant |
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$ 625,000
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Common Stock Price | $ / shares |
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$ 5.40
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March 2020 Maxim Warrant |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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20,400
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Prefunded common stock purchase warrants | April 2020 public offering |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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475,000
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Common stock purchase warrants | April 2020 public offering |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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475,000
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1,525,000
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Exercise price of warrants | $ / shares |
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$ 3.25
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April 2020 Maxim Warrant |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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15,000
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100,000
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15,000
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15,000
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15,000
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Exercise price of warrants | $ / shares |
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$ 3.90
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Fair value of warrant |
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$ 106,000
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Common Stock Price | $ / shares |
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$ 15.80
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$ 2.50
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$ 15.80
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$ 15.80
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$ 15.80
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Combined shares price | $ / shares |
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$ 0.20
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$ 0.20
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Issuance of common stock upon warrant exchanged | shares |
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20,722
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20,722
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April 2020 Maxim Warrant | April 2020 public offering |
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Class of Stock [Line Items] |
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Warrants to purchase shares of Common Stock | shares |
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100,000
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291,000
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Exercise price of warrants | $ / shares |
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$ 3.90
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Dividend Yield | June 4th Purchase Agreement |
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Class of Stock [Line Items] |
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Measurement input |
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0.0
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0.0
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0.0
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Dividend Yield | June 8th Purchase Agreement |
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Class of Stock [Line Items] |
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Measurement input |
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0.0
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0.0
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0.0
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Dividend Yield | April 2020 public offering |
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Class of Stock [Line Items] |
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Measurement input |
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0.0
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Dividend Yield | Warrant | Lisa Walsh |
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Class of Stock [Line Items] |
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Measurement input |
0.0
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Dividend Yield | Warrant | Common Shares |
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Class of Stock [Line Items] |
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Measurement input |
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0.0
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0.0
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0.0
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Dividend Yield | Warrant | January 2021 [Member] |
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Class of Stock [Line Items] |
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Measurement input |
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0.0
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Dividend Yield | March 2020 Warrant |
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Class of Stock [Line Items] |
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Measurement input |
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0.0
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Dividend Yield | April 2020 Maxim Warrant |
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Class of Stock [Line Items] |
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Measurement input |
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0
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Volatility | June 4th Purchase Agreement |
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Class of Stock [Line Items] |
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Measurement input |
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64.0
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64.0
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64.0
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Volatility | June 8th Purchase Agreement |
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Class of Stock [Line Items] |
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Measurement input |
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64.0
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64.0
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64.0
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Volatility | April 2020 public offering |
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Class of Stock [Line Items] |
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Measurement input |
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64.0
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Volatility | Warrant | Lisa Walsh |
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Class of Stock [Line Items] |
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Measurement input |
60.7
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Volatility | Warrant | Common Shares |
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Class of Stock [Line Items] |
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Measurement input |
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60.7
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60.7
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60.7
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Volatility | Warrant | January 2021 [Member] |
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|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
|
60.1
|
|
|
|
|
|
|
|
|
|
|
|
Volatility | March 2020 Warrant |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
|
|
|
61.0
|
|
|
|
|
|
|
|
|
|
Volatility | April 2020 Maxim Warrant |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
|
|
64
|
|
|
|
|
|
|
|
|
|
|
Risk-free rate of interest | June 4th Purchase Agreement |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
0.45
|
|
|
|
0.45
|
|
|
0.45
|
|
|
|
|
|
Risk-free rate of interest | June 8th Purchase Agreement |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
0.32
|
|
|
|
0.32
|
|
|
0.32
|
|
|
|
|
|
Risk-free rate of interest | April 2020 public offering |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
|
|
0.37
|
|
|
|
|
|
|
|
|
|
|
Risk-free rate of interest | Warrant | Lisa Walsh |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
0.78
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Risk-free rate of interest | Warrant | Common Shares |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
0.77
|
|
|
|
0.77
|
|
|
0.77
|
|
|
|
|
|
Risk-free rate of interest | Warrant | January 2021 [Member] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
|
0.45
|
|
|
|
|
|
|
|
|
|
|
|
Risk-free rate of interest | March 2020 Warrant |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
|
|
|
0.38
|
|
|
|
|
|
|
|
|
|
Risk-free rate of interest | April 2020 Maxim Warrant |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measurement input |
|
|
|
|
0.37
|
|
|
|
|
|
|
|
|
|
|
Term (Years) | June 4th Purchase Agreement |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Fair Value Expected Term |
|
|
|
|
|
|
|
|
|
5 years 6 months
|
|
|
|
|
|
Term (Years) | June 8th Purchase Agreement |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Fair Value Expected Term |
|
|
|
|
|
|
|
|
|
5 years 6 months
|
|
|
|
|
|
Term (Years) | April 2020 public offering |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Fair Value Expected Term |
|
|
|
|
5 years
|
|
|
|
|
|
|
|
|
|
|
Term (Years) | Warrant | Lisa Walsh |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Fair Value Expected Term |
5 years 4 months 24 days
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Term (Years) | Warrant | Common Shares |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Fair Value Expected Term |
|
|
5 years
|
|
|
|
|
|
|
|
|
|
|
|
|
Term (Years) | Warrant | January 2021 [Member] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Fair Value Expected Term |
|
|
|
5 years
|
|
|
|
|
|
|
|
|
|
|
|
Term (Years) | March 2020 Warrant |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Fair Value Expected Term |
|
|
|
|
|
5 years
|
|
|
|
|
|
|
|
|
|
Term (Years) | April 2020 Maxim Warrant |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Fair Value Expected Term |
|
|
|
|
5 years
|
|
|
|
|
|
|
|
|
|
|
Series A Preferred Stock | Lisa Walsh |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Class of Stock [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Issuance of common stock upon warrant exchanged | shares |
|
|
|
|
|
|
187,500
|
|
|
|
|
|
|
|
|